It’s common courtesy for visiting dignitaries to present a small token of appreciation or memento to hosts when they visit their country. It’s basic courtesy to receive such gifts, too.

But two Indian Air Force pilots who flew China’s Defense Minister General Liang Guanglie from Mumbai to New Delhi on Monday were perhaps unprepared for the gift they received: 50,000 rupees ($900) each, in sealed envelopes, known in China as a hong bao — meaning red envelope.

The Chinese side was perhaps equally unaware of the implications of their gesture.

The pilots gracefully accepted the ‘gift’ envelopes thinking it to be a pen set or some small gift. But when cash tumbled out, they were left baffled.